The present invention is directed to a fastening element setting tool including a guide sleeve axially displaceable for a limited extent relative to a housing. A bolt guide is arranged coaxially with and forwardly in the driving or setting direction relative to the guide sleeve. A receiving sleeve is axially displaceable to a limited extent relative to and at least partially laterally encloses the bolt guide. The receiving sleeve has a stop face directed in the setting direction and it cooperates with a stop face on the bolt guide for axially limiting the displacement of the receiving sleeve in the setting direction. Further, the receiving sleeve has a stop face directed opposite to the setting direction and cooperating with a stop face directed in the setting direction for axially limiting the displacement of the receiving sleeve opposite to the setting direction.
Fastening element setting tools of the above type are operated by igniting explosive powder or propellant charges introduced into the setting tool. When the propellant charge is ignited a displacing force acts on a piston within the tool, and the piston, in turn, acts upon the fastening element to be driven into a surface of a structural member. The fastening element is supported in a fastening element or bolt guide in known fastening element setting tools and the bolt guide is disposed coaxially to a guide sleeve and is axially displaceable to a limited extent relative to the housing of the setting tool so that it can be positioned ready for ignition. The guide sleeve serves to receive the piston.
When the propellant charge is ignited the gases generated act on the piston and the fastening element and a rebound or recoil occurs acting opposite to the setting direction due to the explosive gas pressure expanding in all directions. Such rebound can be easily absorbed by the operator of the fastening elements tool, however, a momentary lift-off of the setting tool along with the bolt guide takes place relative to the structural member into which the fastening element is driven. The lift-off of the fastening element setting tool acts opposite to the contact pressure force exerted by the operator, so that immediately after the temporary lift-off, the setting tool with its bolt guide again strikes the surface into which the fastening element is driven. Depending on the attention of the operator, such impact can act on the driven fastening element or on the surface around the fastening element.
The resulting impact can cause disadvantages depending on the character of the surface into which the fastening element is driven, for instance, the surface can be damaged or it can be marked in an unsightly manner. Such impact can be particularly troublesome if sensitive parts are to be secured to the surface, for instance, cable channels or conduits formed of a plastics material. If the fastening element setting tool with its bolt guide strikes a cable channel or a similar plastics part, damage can be caused by cracking which may result in an unserviceable part.
To prevent damage to the surfaces of structural members receiving the fastening elements, the setting tools have so-called surface concrete devices involving an inert mass displaceable relative to the bolt guide. Such a fastening element setting tool is disclosed in DE-PS 25 49 196. In such an arrangement, a guide sleeve is supported in a housing so as to be axially displaceable to a limited extent with a coaxially arranged bolt guide projecting in the setting direction outwardly from the guide sleeve. The surface concrete device in the form of a receiving sleeve partially encloses the bolt guide and it is axially displaceable to a limited extent. A shank screw serves for limiting the axial displaceability of the receiving sleeve with the screw extending into a longitudinally extended groove in the bolt guide for forming stops. The stops are arranged so that the leading end face of the receiving sleeve can be displaced opposite to the setting direction beyond the leading end face of the guide. The stops assure that in the setting direction the leading end face of the receiving sleeve projects slightly beyond the leading end face of the bolt guide.
This known arrangement only partially protects the surface of the structural members or components into which the fastening element is driven, that is, only with the known effects of the surface concrete devices. It is possible, however, that a sideways or transverse displacement of the setting tool along with its bolt guide may take place which is not counteracted by this known solution.